 /*******************************************************************************
  * Copyright (c) 2000, 2005 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.core.internal.events;

 import java.util.HashMap ;
 import java.util.Map ;
 import org.eclipse.core.internal.resources.ModelObject;
 import org.eclipse.core.resources.*;
 import org.eclipse.core.runtime.*;

 /**
  * The concrete implementation of <tt>ICommand</tt>. This object
  * stores information about a particular builder, including a reference
  * to the builder instance itself if it has been instantiated.
  */
 public class BuildCommand extends ModelObject implements ICommand {
     /**
      * Internal flag masks for different build triggers.
      */
     private static final int MASK_AUTO = 0x01;
     private static final int MASK_INCREMENTAL = 0x02;
     private static final int MASK_FULL = 0x04;
     private static final int MASK_CLEAN = 0x08;

     /**
      * Flag bit indicating if this build command is configurable
      */
     private static final int MASK_CONFIGURABLE = 0x10;
     
     /**
      * Flag bit indicating if the configurable bit has been loaded from
      * the builder extension declaration in XML yet.
      */
     private static final int MASK_CONFIG_COMPUTED = 0x20;

     private static final int ALL_TRIGGERS = MASK_AUTO | MASK_CLEAN | MASK_FULL | MASK_INCREMENTAL;

     protected HashMap arguments;
     
     /**
      * The builder instance for this command. Null if the builder has
      * not yet been instantiated.
      */
     protected IncrementalProjectBuilder builder;

     /**
      * The triggers that this builder will respond to. Since build triggers are not
      * bit-maskable, we use internal bit masks to represent each
      * trigger (MASK_* constants). By default, a command responds to all
      * build triggers.
      */
     private int triggers = ALL_TRIGGERS;

     /**
      * Returns the trigger bit mask for the given trigger constant.
      */
     private static int maskForTrigger(int trigger) {
         switch (trigger) {
             case IncrementalProjectBuilder.AUTO_BUILD :
                 return MASK_AUTO;
             case IncrementalProjectBuilder.INCREMENTAL_BUILD :
                 return MASK_INCREMENTAL;
             case IncrementalProjectBuilder.FULL_BUILD :
                 return MASK_FULL;
             case IncrementalProjectBuilder.CLEAN_BUILD :
                 return MASK_CLEAN;
         }
         return 0;
     }

     public BuildCommand() {
         super(""); //$NON-NLS-1$
 this.arguments = new HashMap (0);
     }

     public Object clone() {
         BuildCommand result = null;
         result = (BuildCommand) super.clone();
         if (result == null)
             return null;
         result.setArguments(getArguments());
         //don't let references to builder instances leak out because they reference trees
 result.setBuilder(null);
         return result;
     }

     /**
      * Computes whether this build command allows configuration of its
      * triggers, based on information in the builder extension declaration.
      */
     private void computeIsConfigurable() {
         triggers |= MASK_CONFIG_COMPUTED;
         IExtension extension = Platform.getExtensionRegistry().getExtension(ResourcesPlugin.PI_RESOURCES, ResourcesPlugin.PT_BUILDERS, name);
         if (extension != null) {
             IConfigurationElement[] configs = extension.getConfigurationElements();
             if (configs.length != 0) {
                 String value = configs[0].getAttribute("isConfigurable"); //$NON-NLS-1$
 setConfigurable(value != null && value.equalsIgnoreCase(Boolean.TRUE.toString()));
             }
         }
     }

     /* (non-Javadoc)
      * Method declared on Object
      */
     public boolean equals(Object object) {
         if (this == object)
             return true;
         if (!(object instanceof BuildCommand))
             return false;
         BuildCommand command = (BuildCommand) object;
         // equal if same builder name and equal argument tables
 return getBuilderName().equals(command.getBuilderName()) && getArguments(false).equals(command.getArguments(false)) && triggers == command.triggers;
     }

     /**
      * @see ICommand#getArguments()
      */
     public Map getArguments() {
         return getArguments(true);
     }

     public Map getArguments(boolean makeCopy) {
         return arguments == null ? null : (makeCopy ? (Map ) arguments.clone() : arguments);
     }

     public IncrementalProjectBuilder getBuilder() {
         return builder;
     }

     /**
      * @see ICommand#getBuilderName()
      */
     public String getBuilderName() {
         return getName();
     }

     /* (non-Javadoc)
      * Method declared on Object
      */
     public int hashCode() {
         // hash on name alone
 return 37 * getName().hashCode() + triggers;
     }

     /**
      * @see ICommand#isBuilding(int)
      */
     public boolean isBuilding(int trigger) {
         return (triggers & maskForTrigger(trigger)) != 0;
     }

     public boolean isConfigurable() {
         if ((triggers & MASK_CONFIG_COMPUTED) == 0)
             computeIsConfigurable();
         return (triggers & MASK_CONFIGURABLE) != 0;
     }

     /**
      * @see ICommand#setArguments(Map)
      */
     public void setArguments(Map value) {
         // copy parameter for safety's sake
 arguments = value == null ? null : new HashMap (value);
     }

     public void setBuilder(IncrementalProjectBuilder builder) {
         this.builder = builder;
     }

     /**
      * @see ICommand#setBuilderName(String)
      */
     public void setBuilderName(String value) {
         //don't allow builder name to be null
 setName(value == null ? "" : value); //$NON-NLS-1$
 }

     /**
      * @see ICommand#setBuilding(int, boolean)
      */
     public void setBuilding(int trigger, boolean value) {
         if (!isConfigurable())
             return;
         if (value)
             triggers |= maskForTrigger(trigger);
         else
             triggers &= ~maskForTrigger(trigger);
     }

     /**
      * Sets whether this build command allows its build triggers to be configured.
      * This value should only be set when the builder extension declaration is
      * read from the registry, or when a build command is read from the project
      * description file on disk. The value is not otherwise mutable.
      */
     public void setConfigurable(boolean value) {
         triggers |= MASK_CONFIG_COMPUTED;
         if (value)
             triggers |= MASK_CONFIGURABLE;
         else
             triggers = ALL_TRIGGERS;
     }
     
     /**
      * For debugging purposes only
      */
     public String toString() {
         return "BuildCommand(" + getName() + ")";//$NON-NLS-1$ //$NON-NLS-2$
 }
 }

